Alarms water flow

Failure of water pressure can spell disaster in laboratories where some operations, such as distillations, are dependent on water. Ideally, an audible alarm would indicate the lack of water pressure. Laboratory supply houses sell water flow indicators that can be placed in series with the water line to equipment. When water is flowing, a brightly colored ball in a clear tube will move or a small propeller will turn. These can be observed from a considerable distance by watchful laboratory personnel. 

Alarm Activation - all systems should be fitted with alarms that will indicate if water flow has occurred. The alarm activation should occur with the activation of one sprinkler head and usually simulated by the fitting of an orifice at the inspectors test outlet. 

Water spray systems should be provided with a water flow alarm installed in accordance with NFPA13, Installation of Sprinkler Systems. Electrically oper-... 

Chemically mediated interactions have important direct and indirect effects on communities from both ecological and evolutionary standpoints.22 341 Chemical defense or communication cannot be properly understood unless it is viewed through the lenses of population, community, and ecosystem processes, and this requires consideration of both the biotic and abiotic components of the natural environment.342 For example, chemically mediated foraging is affected by water flow because it relies on water-soluble cues that are carried away from prey.343 345 Similar constraints likewise modify the effectiveness of other waterborne cues, such as alarm signals, sexual pheromones, and settlement cues, in both mobile and sessile organisms.244 345 350... 

The temperature profile along the reactor bed may range from a maximum 500 "C close to the reactor inlet, dovra to around 150 C at the exit to the catalyst bed hot-spot temperatures can reach 600 C [ICI68]. The exit gas temperature may reach up to 200 C [ICI69]. The cooling water flow rate is carefully monitored, since its failure could result in severe corrosion as a result of temperature runaway. A temperature alarm, fitted to the jackets, is employed, and is commonly set at around 40 C. 

A wide variety of sensing and initiating devices are available that can detect heat, smoke, radiant energy, and fire gas products. These devices should be selected based upon the type of fire anticipated. Additionally, sprinkler system water flow, activation of other extinguishing systems, and manual fire alarm pull stations can also be used to initiate an alarm signal. 

On one occasion, the computer received a signal indicating a low oil level in a gearbox. The computer reacted as the requirements specified It sounded an alarm and left everything as it was. By coincidence, a catalyst had just been added to the reactor, but the computer had only started to increase the cooling-water flow to the reflux condenser the flow was therefore kept at a low rate. The reactor overheated, the relief valve lifted, and the content of the reactor was discharged into the atmosphere. 

A variation of the dry-pipe system is the deluge system. The sprinkler heads are continuously open and water is prevented from entering the system by a deluge valve. When a fire is detected the valve to the water supply opens and water flows into the system and out of aU the sprinkler heads. This not only wets the immediate area of a small fire, but the entire area to which the fire may spread. This type of system is usually chosen when the contents of the space are unusually hazardous. A variation on this system is the pre-action system in which the sprinkler heads are not open, but when a fire is detected the deluge valve opens and water is supplied to the sprinkler heads. The water entering the system causes an alarm to be sounded. When the heat causes the sprinkler heads to fuse, or open, water is discharged onto the fire. 

The B6580/81 automatic sprinkler system also sen/es the HCF. Standard spray automatic sprinklers are provided in occupied areas of the basement, including Rooms 100,104,105,106, 107, 111, 112,113,113Aand114. The HCF is equipped with an independent fire-alarm control panel, located against the south end of the west wall of Room 107 that monitors all areas of the HCF. Water that may be released during fires is captured and routed to holding tanks. This capture system is described in Section 2.9.5. Any sprinkler-water flow will activate the TA-V... 

Check valve if water flow alarm is used and no other check has been... 

Water Flow Indicator—A water flow indicator and electric alarm may be installed as a primary alarm in place of an alarm valve and water motor alarm however, a check valve must be provided in the system. 

The wet pipe sprinkler system consists of a single riser with water flow indicator and electric alarm feeding, sprinkler heads. 

When a Are occurs, the heat produced will fuse a sprinkler, causing water to flow. The waterflow indicator is activated by the water flow. The paddle, which normally lies motionless inside the pipe, is forced up, thereby activating the pneumatic time delay mechanism, which closes or opens a microswitch after the preset retard time has elapsed. This action causes an electric alarm to sound. The alarm will continue to sound as long as there is a flow of water in the system. The water will flow until it is shut off manually. 

All systems should receive a visual inspection each quarter. Test or inspect each antomatic system on an annual basis. Include all systems in the preventive maintenance plan. Test all snpervisory signal devices except valve tamper switches on a quarterly basis. Test valve tamper switches and water flow devices semiannually. Test duct detectors, electromechanical releasing devices, heat detectors, manual fire alarm boxes, and smoke detectors on a semiannual basis. Test occupant alarm notification devices to inclnde andible and visible devices at least annually. Maintain appropriate documentation on all tire-related system testing. 

To remove heat from the system, water firom the bottom of the column is circulated through a cooling water exchanger to the spray nozzles. The circulating water flow is measured and transmitted to the main control center. Low flow activates an alarm. 

Bearing metal temperatures, oil flow and/or pressure, oil levels, cooling water flow and/or pressure are continuously monitored and alarmed in the control room. 

If water cooling cannot be avoided, the cooling water flow should not be pressurised, but preferably under negative pressure i.e. use a siphon for water flow. Provide an alarm for disraptions in water flow. 

Routine tests should be made of the alarm weekly inspections to show that the stop valves are secured open, separate water supplies are in order, the water and air pressures are adequate and water loads in tanks are acceptable, and quarterly to check the water flow through each system and to ensure that the required flow characteristics are maintained. 

MORE MORE COOLING WATER FLOW FAILURE OF l/L CONTROL VALVE PROCESS FLUID TEMPERATURE LO LO INSTALL C.WATER FLOW ALARM HI... 

In modem sprinkler systems (shown diagrammatically in Figure 4.2.10) water is supplied at pressure from tire town mains which charges a pressure tank. When a sprinkler head mptures, the loss of water pressure in the supply pipe triggers the alarm valve. The alarm is actuated by the alarm valve either by diverting part of tire water flow to a hydraulic gong or by actuating an electrical alarm. The pressure tank acts as a buffer to absorb any water hammer effects and to provide a temporary water supply if the mains flow is intermpted. 

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